Respiration In Birds Research Articles

No Signs of Adaptations for High Flight Intensity in the Mitochondrial Genome of Birds.

Mitochondrial genomes are expected to show adaptations for optimizing aerobic respiration in birds that make intense use of flight. However, there is limited empirical evidence of such a relationship. We here examine correlates of several mitochondrial genome characteristics and flight use across a diverse sample of 597 bird species. We developed an index of flight use intensity that ranged from 0 in flightless species to 9 in migratory hummingbirds and examined its association with nucleobase composition, amino acid class composition, and amino acid site allelic variation using phylogenetic comparative methods. We found no evidence of mitochondrial genome adaptations to flight intensity. Neither nucleotide composition nor amino acid properties showed consistent patterns related to flight use. While specific sites in mitochondrial genes exhibited variation associated with flight intensity, there was limited association between specific amino acid residues and flight intensity levels. Our findings suggest a complex genetic architecture for aerobic performance traits, where multiple genes in both mitochondria and the nucleus may contribute to overall performance. Other factors, such as gene expression regulation and anatomical adaptations, may play a more significant role in influencing flight performance than changes in mitochondrial genes. These findings highlight the need for comprehensive genomic analyses to unravel the intricate relationship between genetic variants and aerobic performance in birds.

Measurement and Analysis of Radar Signals Modulated by the Respiration Movement of Birds

Once, bird respiration was thought to be responsible for the 10 dB-level fluctuations in the radar signals of birds. Although, recently, many researchers provide evidence against this, there are almost no quantification measurements of the contribution of respiration to bird signals in microwave anechoic chambers. Here, we first measured the radar signals modulated by the respiration of birds in a microwave anechoic chamber. Theoretically, the simulated signal fluctuation caused by the respiration of a 1 kg standard avian target (SAT) duck is approximately 1.2 dB based on the water sphere model. Then, experimentally, in a microwave anechoic chamber, we measured the signal fluctuations produced by the respiration movement of ducks using a dynamic system composed of a network analyzer and a high-speed camera. We tracked continuous radar data of a living duck and a dead duck within the S-band, X-band, and Ku-band, and then presented them using low-resolution range profiles (LRRP) and high-resolution range profiles (HRRP). The results indicate that respiration movement causes periodic signal fluctuation with a respiration rate of approximately 0.7 Hz, but the amplitudes within S-band, X-band, and Ku-band are approximately 1 dB level, much less than the 10 dB level. Respiration is not responsible for the 10 dB-level periodic signal fluctuation in radar echoes from birds.

Coordination of wingbeat and respiration in birds. II. "Fictive" flight.

To determine whether an interaction between central respiratory and locomotor networks may be involved in the observed coordination of wingbeat and respiratory rhythms during free flight in birds, we examined the relationship between wingbeat and respiratory activity in decerebrate Canada geese and Pekin ducks before and after paralysis. Locomotor activity was induced through electrical stimulation of brain stem locomotor regions. Respiratory frequency (fv) was monitored via pneumotachography and intercostal electromyogram recordings before paralysis and via intercostal and cranial nerve IX electroneurogram recordings after paralysis. Wingbeat frequency (fW) was monitored using pectoralis major electromyogram recordings before, and electroneurogram recordings after, paralysis. Respiratory and cardiovascular responses of decerebrate birds during active (nonparalyzed) and "fictive" (paralyzed) wing activity were qualitatively similar to those of a variety of vertebrate species to exercise. As seen during free flight, wingbeat and respiratory rhythms were always coordinated during electrically induced wing activity. Before paralysis during active wing flapping, coupling ratios (fW/fv) of 1:1, 2:1, 3:1, and 4:1 (wingbeats per breath) were observed. After paralysis, fW and fv remained coupled; however, 1:1 coordination predominated. All animals tested (n = 9) showed 1:1 coordination. Two animals also showed brief periods of 2:1 coupling. It is clear that locomotor and respiratory networks interact on a central level to produce a synchronized output. The observation that the coordination between fW and fv differs in paralyzed and nonparalyzed birds suggests that peripheral feedback is involved in the modulation of a centrally derived coordination.

Tests of Six Continuous Flow CPAP Devices

Six continuous flow CPAP devices were tested for pressure fluctuation and stability of inhaled oxygen concentration under conditions of simulated respiration. Four of the systems, the Ambu, Auspap, Downs'-Vital Signs and the Dräger are commercially available and two, the Prince Henry (PHH) and the Prince of Wales (POW) systems were assembled from Bird respirator parts, which were available in the respective Intensive Care Units. All appeared to be clinically effective. The Ambu offers convenience and economy of gases, the Dräger showed the least pressure fluctuations. Three of the four commercial systems lacked certain safety features which could more easily be added to the two non-commercial devices.

DSM-III-R schizotypal personality features and disorder in offspring, siblings and parents of schizophrenic disorder, affective disorder, and normal control parent probands

This chapter describes normalization of embryonic respiration in birds at high altitude. According to Fick's law of diffusion, it can be shown that gaseous exchange at altitude is normalized when the respiratory gas tensions in the air space of an egg are restored to sea level values and when, simultaneously, the partial pressure gradients of O2, CO2, and H2O are reduced in accordance with the increase of the shell conductance. This condition can be achieved by an increase of the ambient O2 and CO2 concentrations, and an increase of relative humidity. A model was calculated for a typical chicken egg weighing 63 g. After 17–19 days of incubation, the O2 consumption of the embryo is 675 ml (STPD)/day. Its CO2 production is 486 ml (STPD)/day and the egg loses 378 mg H2O.day−1. In the air spaces between the inner membrane and the egg shell, the PO2 = 107.7 Torr and the PCO2 = 38.7 Torr. When the same egg is to be incubated at an altitude of 5.5 km, the fractional O2 concentration around the egg must increase to 0.385 and the fractional CO2 concentration to 0.066 to maintain the same gaseous exchange and the same air space gas tensions as at sea level.

High-altitude respiration of birds. Structural adaptations in the major and minor hemoglobin components of adult Rüppell's Griffon (Gyps rueppellii, Aegypiinae): a new molecular pattern for hypoxic tolerance.

The primary structures of the hemoglobins Hb A, Hb A', Hb D and Hb D' of Rüppell's Griffon (Gyps rueppellii), which can fly as high as 11,300 m, are presented. The globin chains were separated on CM-Cellulose in 8M urea buffers, the four hemoglobin components by FPLC in phosphate buffers. The amino-acid sequences of five globin chains were established by automatic Edman degradation of the globin chains and of the tryptic peptides in liquid-phase and gas-phase sequenators. The sequences are compared with those of other Falconiformes. A new molecular pattern for survival at extreme altitudes is presented. For the first time four hemoglobins are found in blood of a bird; they show identical beta-chains and differ in the alpha A- and alpha D-chains by only one replacement. These four hemoglobins cause a gradient in oxygen affinities. The two main components Hb A and Hb A' differ at position alpha 34 Thr/Ile. In case of Ile as found in Hb A' an alpha 1 beta 1-interface is interrupted raising oxygen affinity compared to Hb A. In addition the hemoglobins of the A- and D-groups differ at position alpha 38 Pro or Gln/Thr (alpha 1 beta 2-interface). Expression of Gln in Hb D/D' raises the oxygen affinity of these components compared to Hb A/A' by destabilization of the deoxy-structure. The physiological advantage lies in the functional interplay of four hemoglobin components. Three levels of affinity are predicted: low affinity Hb A, Hb A' of intermediate affinity, and high affinity Hb D/D'. This cascade tallies exactly with oxygen affinities measured in the isolated components and predicts oxygen transport by the composite hemoglobins over an extended range of oxygen affinities. It is contended that the mechanisms of duplication of the alpha-genome (creating four hemoglobins) and of nucleotide replacements (creating different functional properties) are responsible for this remarkable hypoxic tolerance to 11,300 m. Based on this pattern the hypoxic tolerances of other vultures are predicted.

Metabolite levels in control and anoxic chicken liver while employing a technique for artificial respiration in birds

1. 1. Physiological levels of blood gases can be maintained in an anaesthetized, abdominally opened fowl by means of a simple unidirectional ventilation technique. 2. 2. ATP levels and ATP/ADP ratios in control birds measured using the ventilation technique have been found to be much higher than previously reported and are comparable to those reported in rats. 3. 3. Lactate levels and the lactate:pyruvate ratio were much lower in controls than is reported for nonventilated chickens. 4. 4. An increase in the tissue content of glucose in anoxia suggests increased hepatic glycogen breakdown. 5. 5. Rises in the tissue concentration of AMP and inorganic phosphate in anoxic liver are consistent with an activation of glycogen phosphorylase; the rise in AMP and fructose-1,6-bisphosphate, and fall in ATP, with an activation of phosphofructokinase; and the rise in fructose-1,6-bisphosphate and ADP and fall in ATP, with an activation of pyruvate kinase—all indicative of the increased glycolytic flux in anoxic chicken liver.

Metabolite levels in fed and fasted chicken liver and kidney while employing a technique for artificial respiration in birds

1. 1. A six-day fast in chickens results in a 55% drop in hepatic glucose but no change in renal glucose. 2. 2. Measures of cellular energy level in the liver of fasted chickens increase on a six-day fast, in contrast to the kidney where no change is observed. 3. 3. The cytosol of chicken liver becomes oxidized upon fasting, while the redox state of the kidney cytosol remains unchanged. 4. 4. We conclude that the process of gluconeogenesis from amino acids and pyruvate is more favoured in the kidney of a fasted chicken than in its liver.

Role of thyroid in tissue respiration of birds

Thyroidectomy after 1 week, 1 month, and 13 months significantly depressed and low level of l-T 4 significantly elevated the oxygen uptake of the liver and skeletal muscle of spotted munia and common myna. A higher dose of l-T 4 had no effect on the rate of respiration. A reexamination of the published results on submammalian vertebrates together with those presented here suggests that an uniform pattern of response of skeletal muscle emerges if the values from thyroidectomized animals are compared not only with the final controls but also with the initial controls. It is, therefore, suggested that all the earlier works be reexamined and reinterpreted.

Respiration in Birds

INTRODUCTION TO THE SYMPOSIUMOn August 8, 1979, a symposium entitled “Respiration in Birds” was presented to the 68th Annual Poultry Science Association Meeting held at the University of Florida, Gainesville, Florida. This symposium was sponsored by the physiology section; however, the purpose was not to exclusively consider the anatomic and physiologic aspects of the respiratory system, but also to integrate this knowledge with more applied concerns. Two of the four papers of the symposium dealt with the basic anatomy and physiology of the system, one paper concerned pathology of the respiratory apparatus, and the final paper concerned management of the climatic factors which constitute the environments of commercially reared birds.Roger Fedde of Kansas State University presented the first paper, “Structure of an Air Flow Pattern in the Avian Respiratory System”. Results were presented of numerous studies from laboratories in the US and especially those in West Germany concerned .

The Bird Respirator Modified for PEEP, CPAP and IMV

A Bird Mk. 8 respirator has been modified to permit the use of PEEP, CPAP and IMV. Gas supply is from an oxygen blender to allow easy adjustment of the inhaled oxygen concentration. A special fitting was made to mount a flow meter which supplies the IMV reservoir. PEEP is generated by the Mk. 8 negative pressure generator mounted in opposition to exhalation and its magnitude can be adjusted by the negative pressure control of the respirator. This modified machine is simple, reliable and relatively inexpensive.

1177 VENTILATOR MANAGEMENT AND PNEUMOTHORAX IN NEONATES WITH RDS

An apparent doubling of the incidence of pneumothorax in premature neonates mechanically ventilated for RDS prompted a comparison of ventilator therapy in these patients, past and present. In 1973-75, 16 of 16 infants treated for RDS developed pneumothorax/pneumomediastinum/pneumopericardium (PN) after intermittent mandatory ventilation using a Baby Bird respirator, while in 1976-77 the frequency of PN increased to 28 of 54 patients ventilated (p < 0.03). Record review demonstrated no differences in birth weight, severity of disease, age at intubation, interval from intubation to PN or mortality. Ventilator settings immediately prior to clinical evidence of PN showed similar peak pressures, PEEP, and FiO2. However, there were significant differences (p <0.01) in ventilator rates and flow rates:Between these periods a change in ventilator policy to using longer inspiratory times occurred. The association between lower flow and ventilatory rates and a higher incidence of PN suggests that either variable alone or in combination with longer inspiratory times may increase the risk for alveolar rupture and development of pneumothorax.

Hemodynamics of the Pulmonary Circulation in Patients on Intermittent Positive Pressure Breathing With a Bird Respirator

Hemodynamics of the Pulmonary Circulation in Patients on Intermittent Positive Pressure Breathing With a Bird Respirator

Pulmonary gas exchange: a comparison of the effects of sighs using helium and oxygen with the effects of positive expiratory pressure plateau.

A comparison of periodic hyperinflations or “sighs” and positive expiratory pressure plateau (PEFP) was done in ten post-operative cardiac patients. Highly significant decreases in shunts (Qs/Qt) and highly significant increases in PaO2 occurred with PEPP. Improvement in ventilation. occurred with “sighs” but no change in oxygenation or perfusion was observed. A BIRD respirator was used and was adapted to PEPP.

Tracheal Dead Space in the Respiration of Birds

Tracheal Dead Space in the Respiration of Birds

The co-ordination between respiration and wing beats in birds

Investigations in 10 species showed that respiration of birds in flight is usually co-ordinated with wing beats, but the co-ordination is not obligatory. Respiration synchronous with wing beats (1∶1 co-ordination) was found only in pigeons and crows, the other species exhibited one of 11 other types of co-ordination. Quails, ducks and pheasants, birds with relatively high wing beat frequencies (with relatively small wings) showed a 5∶1 co-ordination. Within species, and even during a flight the type of co-ordination changed, and simultaneously there were sudden changes in the respiration frequency. For the most part, the beginning of inspiration was linked with the (end of) upstroke and the beginning of expiration with the end of downstroke.

Dynamics of the blood flow in the myocardial tissue

For myocardial tissue blood flow measurements, the flexible and thread-like cross thermocouple probes were implanted into the interior of the left ventricular wall, and the regional distribution of the blood flow and the generation mechanisms for the blood flow wave were examined. Methods 1. Preparation Mongrel dogs weighing from 17 to 25kg were anesthetized with pentobarbital sodium, 35 to 45 mg/kg, i.v. The arterial Po2 was maintained to normal level by a Bird's respirator. The chest was opened by resecting the first to 8th ribs of the left side. After pericardiectomy, the cross thermocouple probes were implanted into the interior of the anterior aspect of the left ventricle to settle the two junctions of the probes nearly in the same distance from either the epicardium or endocardium. Then, the straingauge bridges were sewn onto the adjacent area for tension measure-production and heat or temperature conductivity ments. A monopolar electrode for e.k.g. was also attached to the wall close to the probes. There-after, the probes of electromagnetic flowmeter were set on the ascending aorta, pulmonary artery, anterior descending branch and circumflex branch of the left coronary artery and to the coronary vein (Fig. 2). 2. Cross Thermocouple Probes (Fig.1 and 3) The probes for heat clearance method are made of copper and constantan threads 100μ in diameter. The distance between the heated junction (D in Fig.1) and the reference one (E) is from 4 to 5mm. The heated junction was heated by 50 mA. AC to maintain its temperature about 3°C above that of the tissue. A spine about 100μ in length was attached to the heated junction to prevent slipping of it during myocardial contraction (Fig. l). a) A temperature gradient of 1°C between the junctions generates 42μV of the thermoelectromotive force. b) The maximum collecting distance (or axial temperature field) in the myocardium is 3.5mm. c) The response time of the probes is from 1 to 3 msec.

Nervous control of the blood flow in the myocardial tissue

Continuously measuring the myocardial tissue blood flow by heat clearance method using the cross-thermocouple probes whose character has been described elsewhere, the roles, in the regulation of the flow, of the sympathetic nerve, vagal nerve, carotid sinus and the sympathetic afferent fibers with the receptor sites in the thoracic cavity were examined in the anesthetized dogs with the results that their role varied considerably by the layers of the left ventricular wall. In this paper, the differences between the nervous control of the coronary blood flow and that of the tissue blood flow and those between the nervous control of the blood flow in the inner layer and that in the outer layer were represented and the possible mechanisms for the differences were discussed. Method s Experiments were carried out on the mongrel dogs, weighing from 18 to 25 kg, anesthetized with pentobarbital sodium (35-45 mg/kg, I.V.). The arterial Po2 was maintained to normal level by a Bird's respirator. The thoracic cavity was opened by resecting the ribs from the first to 8th on the left side. After pericardiectomy, the anterior descending branch of the left coronary artery proximal to its origin was carefully separated from the surrounding connective tissues not to damage the nerves which run close to it. Thereafter, a probe of electromagnetic flow-meter was set on it. In order to measure the myocardial tissue blood flow, a pair of the thermoprobes were implanted into the interior of the left ventricular wall. The two thermojunctions of the probes were settled nearly in the same distance from either the epicardium or endocardium to avoid the influence on the thermoelectromotive force of the temperature gradients, different heat production and different heat or temperature conductivity in the wall. Thereafter, the strain-gauge bridges for tension measurements were sewn onto the wall adjacent to the probes. In addition, a monopolar electrode for e.k.g. was attached to the wall close to the probes. The left stellate ganglion was freed from the surroundings. After transsecting the branches of the central side, the ganglion was placed across a pair of platinum-ilidium stimulating electrodes. The right cervical vagus was prepared in the same way for electrical stimulation. The nerves were stimulated with the electric pulses of 0.5 msec duration, square wave, 12 V, and of 10 cps. The stimulus frequency was altered when necessary from 0.5 up to 10 cps.

Device for control of oxygen concentration with bird respirator

Device for control of oxygen concentration with bird respirator

Notes on uses of the bird respirator treatment by physiotherapy

No abstract available.